My grey REALLY wants to say hi to other dogs

[HazeyJ]

I got my new boy Jack very recently. At first he just didn't acknowledge dogs at all. Now he has more confidence and he REALLY wants to say hi. He's friendly and not aggressive, just has a nice sniff, but the problem is that it's not a great behaviour. He's friendly, but that doesn't mean every other dog he meets will be. He is so big that even if I have his harness on and hold his leash really close, he can still overpower me to run to another dog. 

What's the best way to train this out? He's not that into treats when we're walking outside - and because he's friendly I don't want him to think having a sniff is bad, just the part where he legs it to them with no manners! 

Any advice welcome!

[HeyRunDog]

Use a martingale or fishtail collar instead of a harness as they give you more control. With a harness the dog can pull on the lead using all his body strength. If you are worried about him slipping his collar use a double ended lead with one end attached to the collar and the other to the harness.

Teach him the "Watch me" command so as soon as he seems to take an interest in another dog you can distract him and keep walking.
https://www.battersea.org.uk/pet-advice/dog-advice/how-teach-your-dog-watch-me-command

[Hubcitypam]

My groomer also said a martingale gives you much more control than a harness.  My neighbor does a lot of  "watch me" and "turn around".